Investigators examined the association between parental addictions and adult depression in a sample of 6268 adults and published their results in a journal of Psychiatry Research. Of these respondents, 312 had a major depressive episode within the year preceding the survey and 877 reported that while they were under the age of 18 and still living at home that at least one parent who drank or used drugs “so often that it caused problems for the family.”

The study found that individuals whose parents were addicted to drugs or alcohol are more likely to develop depression than their peers. After adjusting for age, sex and race, parental addictions were associated with more than twice the odds of adult depression, says lead author Esme Fuller-Thomson, Professor and Sandra Rotman Endowed Chair in the University of Toronto’s Factor-Inwentash Faculty of Social Work and the Department of Family and Community Medicine.

This study could not determine the cause of the relationship between parental addictions and adult depression. Co-author Robyn Katz, suggests that “It is possible that the prolonged and inescapable strain of parental addictions may permanently alter the way these children’s bodies reacts to stress throughout their life. One important avenue for future research is to investigate potential dysfunctions in cortisol production — the hormone that prepares us for ‘fight or flight’ -which may influence the later development of depression.”

“These findings underscore the intergenerational consequences of drug and alcohol addiction and reinforce the need to develop interventions that support healthy childhood development,” says Prof. Fuller-Thomson. “As an important first step, children who experience toxic stress at home can be greatly helped by the stable involvement of caring adults, including grandparents, teachers, coaches, neighbors and social workers. Although more research is needed to determine if access to a responsive and loving adult decreases the likelihood of adult depression among children exposed to parental addictions, we do know that these caring relationships promote healthy development and buffer stress.”